The invention relates to the electrophotographic imaging arts. It finds particular application to a method and system of detecting toner dust in an electrophotographic imaging device. It will be appreciated that the present invention will find application in printers, copiers, fax or other imaging devices where toner may cause undesired effects or malfunctions.
In an electrophotographic printer, during an image transfer process between a photosensitive drum and a transfer roller, toner dust particles can migrate from the photosensitive drum, the transfer roller, or from print media into a post transfer area of the printer. These toner dust particles can stick to the leading edge of a page and be carried to a fuser where they can lead to fuser contamination or separation claw contamination. Toner deposits in the fuser can produce fuser contamination effects (e.g. unwanted toner particles on printed media) or mechanical jams.
Typically, an electrophotographic printer also includes a toner waste hopper to collect excess toner from the photosensitive drum. Seals are typically used to contact the surface of the photosensitive drum and are intended to prevent toner stored in the waste hopper from leaking out into the printer. Occasionally, toner leaks from the waste hopper and gets distributed within the interior of the printer, particularly along the path followed by the print media. Leaks may occur due to, for example, an overfilled waste hopper or broken seals.
Toner dust that leaks from the waste hopper or otherwise comes from the image transfer process, tends to move and accumulate in an area near the fuser and transfer roller. Often, the toner dust may attach to the back side of successive print media passing over the transfer roller resulting in a print defect. Fusers are particularly susceptible to contamination from toner dust. Additionally, toner dust can migrate throughout the printer potentially contaminating other components and assemblies causing undesirable print defects and possibly operational defects and component damage.
In accordance with one embodiment of the present invention, an apparatus for detecting toner particles in an electrophotographic imaging device is provided. The apparatus includes a sensor positioned within the imaging device to detect uncontained toner particles. A controller is coupled to the sensor and generates a warning signal when the uncontained toner particles reach a predetermined level.
In accordance with another embodiment of the present invention, a method of detecting toner dust in an electrophotographic imaging device is provided. The method includes moving one or more print media along a printing path within the electrophotographic imaging device. Toner is transferred to the print media at a transfer point along the printing path. An accumulation of toner dust is detected subsequent to the transfer point and a warning signal is generated when the accumulation of toner dust meets a predetermined condition.